Chargers' Russell Okung raises fist during national anthem before preseason game against Cardinals

Russell Okung continued his protest against social injustices and police brutality during the national anthem before Saturday's preseason game at University of Phoenix Stadium.(Photo: Matt Wilhalme/azcentral sports)

Chargers tackle Russell Okung stood with his fist raised during the national anthem Saturday ahead of the Chargers-Cardinals game at University of Phoenix Stadium.

There were no other overt protests, and it wasn’t immediately clear whether any players remained in the locker room.

Okung, one of the leaders pushing for social change among NFL players, raised his fist while remaining standing during the national anthem last season to protest social injustices and police brutality.

Okung wrote an open letter last fall calling for NFL players to be more organized in their protests and lamenting the warping of their protests' original intention.

The protest controversy has taken center stage at University of Phoenix Stadium before.

Before a September game last season at the height of the anthem controversy, Cowboys players and coaches, and team owner Jerry Jones, locked arms and briefly took a knee on the field before the anthem played at University of Phoenix Stadium.

During the anthem, they helped hold a massive flag stretched out on the field.